<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.10/vue.js"></script>
</head>
<body>
<div id="app">
    <p>{{firstName.toLowerCase() + " " + lastName.toLowerCase()}}</p>
</div>
<script>
  const vm = new Vue({
      el:"#app",
      data(){
          return{
            firstName:"Michael",
            lastName:"Jorden"
          }
      },
  })
</script>
</body>
</html>